docs: improve doctests for ndarray instances in ndarray/dcusum

[AyushiJain18270]

Resolves a part of #{{9329}}.

Description

What is the purpose of this pull request?

This pull request:

• improve doctests for ndarray instances in dcusum

Related Issues

Does this pull request have any related issues?

This pull request has the following related issues:

• #{{9329}}

Questions

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No.

Other

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No.

Checklist

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• Read, understood, and followed the contributing guidelines.

AI Assistance

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• No

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• Test/benchmark generation
• Documentation (including examples)
• Research and understanding

Disclosure

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N/A

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[kgryte]

/stdlib merge

[stdlib-bot]

Thank you for working on this pull request. However, we cannot accept your contribution as the issue this pull request seeks to resolve has already been addressed in a different pull request or commit.

Thank you again for your interest in stdlib, and we look forward to reviewing your future contributions.